Cannot connect Outlook 2002 to Exchange 5.5 remotely

[Blackadder222]

Server is running NT4 and Exchange 5.5.
Clients are all running Outlook 2002.

On my internal network there is no problem, Outlook 2002 connects to Exchange normally.

And until yesterday, remote access using Outlook 2002 from my home office was no problem.

But for some reason, since yesterday mid-morning, I cannot get Outlook to connect remotely (from several different clients on different ISP's/connections.

Interestingly, I can still access my Exchange account using IMAP (I'm using Opera's mail client to do so as a temp workround), and remote web access (OWA) is also working fine. Unfortunately this gives only limited functionality!

I'm not sure if it's relevant, but I've discovered that port 135 now seems to be blocked on both client and server machines - however I've no way of knowing whether this was the case before my problem arose. I've been assured by the ISP through which the server is connected that they have not/do not block port 135 (or any ports).

I was wondering if there is any connection with the "blaster" worm that is causing problems currently - although my AV software reports no infection.

I've spent the last 24 hours struggling to find a solution and so far have failed - some guidance would be much appreciated!

 

[dennisbbb]

Your ISP should fired that idiot who took your call.

Port 135 is totally blocked by most ISP to counter this RPC worm. Inhouse users have no problem because your internal network is untouched.. allowing port 135 name resolution of the Exchange server.

A quick way to connect your user is to set him/her up on the good old Pop3/Smtp and give them an offline addressbook.
Address list will not be the latest, but at least now they can't complain that Oulook connects slow.

Good luck.

 

[bschwarting]

I'm having the exact same issue. Mine has been going on for a couple weeks now. All the sudden my exchange server will no longer authenticate externally.

I set up a sniffer on my firewall, and told it to watch everything from my source (home) IP, and when i click on outlook, it normally opens up the user/pass/domain box. It just comes back with "exchange server unavailable." The firewall see's absolutely no traffic coming from my IP.

This is a strange issue. Can anyone answer the below?

Is this authentication all done on port 135?

 

[chicknnhead]

I'm haveing the same problem, so your no alone, i hope someone has found the answer

 

[Blackadder222]

After having spent a chunk of today on the phone to Microsoft, I've confirmed that all my PC's are Blaster-free, and port 135 is open on the server. However, I still can't get through with my Outlook remotely cos somewhere between my client PC and my server, the port is being blocked...

 

[bschwarting]

Looks like it is an issue with the latest virus worm. The virus is sending itself via port 135. Exchange does it's authentication via port 135, so that is our problem.

Here is what I got from my ISP:

"Port 135 is not only being blocked by us, but also by as many as have the upstream providers now. I have no estimates to how long it will take the virus to be killed, which will then result in upstream providers unblocking that port."

A good fix is to allow the pop3 protocol on your exchange server and port forward port 25 and 110 to your exchange server from your firewall. Then you can set up outlook express to retrieve your email.

** Make sure to hit the checkbox "leave copy of mail on server" or else you will remove everything from exchange to your home PC.

Post any questions you might have about that process.